Automatically self-regulating variable-stroke, variable-rate and quiet-operating pile driver method and system

ABSTRACT

Automatically self-regulating variable-stroke, variable-rate and quiet-operating pile driver method and system are disclosed in which a massive piston weight is bounced upon a cushion of pressure fluid, the pile driver advantageously being adapted for operation in four different modes: (1) only double-acting, (2) single-acting automatically converting to double-acting at maximum stroke travel, (3) only single-acting, (4) pre-stressing plus impacting plus thrusting mode, and (5) pile extraction mode. The prolonged downward push resulting from the pressurized fluidcushioned bouncing action is more effective than the conventional sharp hammer-type blow resulting from impact of one solid mass against another. When the pile being driven encounters softer strata in the earth, in the single-acting mode, the stroke of the piston weight automatically shortens while the number of bounces per minute automatically increase thus increasing the rate of the quiet powerful bounce thrusts for driving the pile faster, and when harder strata are encountered, the piston weight automatically bounces higher providing a longer stroke with fewer bounces per minute, thus increasing the force of each quiet powerful thrust for overcoming the increased impedance being encountered. In the double-acting mode, when harder strata are encountered, the velocity and stroke length of the piston weight increase automatically to deliver more powerful thrusts. A relatively large number of driving thrusts per minute can be provided in the double-acting mode by changing the head plug mass to shorten the maximum stroke length to increase the frequency of thrusts per minute. By virtue of the pressure fluid bouncing action imparted to the massive piston weight, the noise of metalto-metal contact blows can be avoided, and in addition a muffler housing surrounding the ports through which the expanded pressure fluid is released muffles the sound of the flow of the fluid, such as air or steam; this muffler also serving to separate lubricating oil from the released fluid. A cylinder bottom assembly below the bounce chamber is coupled to the pile being driven to transmit the quiet powerful bounce thrusts to the pile, moving in accordance with the pile motion, and a driving fluid storage chamber and valve mechanism associated with this assembly control the flow of the pressure fluid in an automatically selfregulating manner to seek the most effective driving action from moment-to-moment as the pile encounters different strata. If desired, the bouncing action of the cushion of pressure fluid can be altered to permit the piston weight to strike bottom slightly to provide the driving mode (4) above. A self-contained lubrication system may be actuated by the pressure impulses in the bounce chamber.

United States Patent 1 1 Chelminski [451 Feb. 6,1973

[ AUTOMATICALLY SELF- REGULATING VARIABLE-STROKE, VARIABLE-RATE ANDQUIET- OPERATING PILE DRIVER METHOD [58] Field of Search..6l/53.5;173/91,135, 139, 173/131, 1; 175/19 [561 References Cited 1UNITED STATES PATENTS 3,583,499 6/1971 Cordes ..l7 3/9l X 3,417,82812/1968 Duyster ct a1. ...6l/53.5 X 1,622,896 3/1927 Lowenstein..l73/l3l X Primary Examiner-Ernest R. Purser AtzorneyBryan, Parmelee,Johnson & Bollinger [57] ABSTRACT Automatically self-regulatingvariable-stroke, variablerate and quiet-operating pile driver method andsystem are disclosed in which a massive piston weight is bounced upon acushion of pressure fluid, the pile driver advantageously being adaptedfor operation in four different modes: (1) only double-acting, (2)single-acting automatically converting to double-acting at maximumstroke travel, (3) only single-acting, (4) pre-stressing plus impactingplus thrusting mode, and (5) pile extraction mode. The prolongeddownwardpush YesiITtTngfroniTlie pfe ssiTzed fluid cfioh d bouncing action ismore effective than the conven-' tional sharp hammer type blow resultingfrom impact of one solid mass against another. When the pile beingdriven encounters softer strata in the earth, in the single-acting mode,the stroke of the piston weight automatically shortens while the numberof bounces per minute automatically increase thus increasing the rate ofthe quiet powerful bounce thrusts for driving the pile faster, and whenharder strata are encountered, the piston weight automatically bounceshigher providing a longer stroke with fewer bounces per minute, thusincreasing the force of each quiet powerful thrust for overcoming theincreased impedance being encountered. 1n the double-acting mode, whenharder strata are encountered, the velocity and stroke length of thepiston weight increase automatically to deliver more powerful thrusts. Arelatively large number of driving thrusts per minute can be provided inthe double-acting mode by'changing the head plug mass to shorten themaximum stroke length to increase the frequency of thrusts per minute.By virtue of the pressure fluid bouncing action imparted to the massivepisto'n weight, the noise of metal-to-metal Contact blows can beavoided, and in addition a muffler housing surrounding the ports throughwhich the expanded pressure fluid is released muffles the sound of theflow of the fluid, such as air or steam; this muffler also serving toseparate lubricating oil from the released fluid. A cylinder bottomassembly below the bounce chamber is coupled to the pile being driven totransmit the quiet powerful bounce thrusts to the pile, moving inaccordancewith the pile motion, and a driving fluid storage chamber andvalve mechanism associated with this assembly control the flow of thepressure fluid in an automatically self-regulating manner to seek themost effective driving action from moment-to-moment as the pileencounters different strata. If desired, the bouncing action of thecushion of pressure fluid can be altered to permit the piston weight tostrike bottom slightly to provide the driving mode (4) above. Aself-contained lubrication system may be actuated by the pressureimpulses in the bounce chamber.

17 Claims, 21 Drawing Figures Feb. 6, 197.3

United States Patent 1191 Chelminski PATENTEDFEB 6 I975 3.714.789

SHEET 2 OF 7 INVENTQR. I Sis 17101 V Cite/mash PATENTEDFEB ems 3.714.789SHEET E OF 7 Jill is Q R @AQ INVENTOR. t Slap/zen V 6' k617i! 015MAUTOMATICALLY SELF-REGULATING VARIABLE-STROKE, VARIABLE-RATE ANDQUIET-OPERATING PILE DRIVER METHOD AND SYSTEM BACKGROUND INFORMATIONConventional pile drivers of the diesel type use a falling piston orthose of the steam type use a falling ram of great weight to strike downupon an anvil surface to transmit the blow to the pile. Suchconventional pile drivers have a disadvantage in the fact that theytransmit the energy of the falling mass by a strikingtype blow on ananvil surface. Each blow produces a very loud noisy sound ofmetal-to-metal contact which is annoying to many persons, includingpersons who are located at a relatively great distance from theconstruction site. This noisy blow, especially in the conventionalsteam-type open striking hammer, is, in my opinion, a

relatively unsatisfactory method of transmitting energy to the pile forthe purpose of driving the pile, because of the suddenness and shortduration of this type of blow. Also, the forces on the anvil and on thepile become destructive when the energy levels needed to drive a pilebecome high.

Because of the metal-to-metal contact, the impact tends to bedestructive to the pile driver itself and to the pile being driven.There are many instances when shock-absorbing materials must beinterposed between the striking parts and the pile. The shock-absorbingmaterials which are conventionally used are wooden blocks, or pads, ofphenolic laminates, or other plastic materials. The use of such shockabsorbers wastes energy, and since they are expendable and need to bereplaced, there is a resulting added cost for the pile drivingoperation.

It can be said that the prior art pile drivers are often noisy.

Another disadvantage inherent in the conventional steam-type pile driverlies in the longer period of time it takes for this type of driver toraise its hammer weight up from the anvil to the top of its travelbefore releasing the steam to expand to atmospheric pressure. The

release of the steam drops the hammer weight to fall upon the anvil.

As further background information, it is noted that there is anadvantage in providing a relatively large number of driving thrusts perminute to a pile being driven. The reason for this advantage is that thesoil adjacent to the pile remains in a more or less agitated state whenfrequent driving thrusts are applied to the pile. Consequently, thefrictional force is reduced and the pile is relatively easier to drive.Conversely, when the driving thrusts are less frequent, the soiladjacent to the pile has an opportunity to slumpdown to become morefirmly seated against the side surfaces of the pile, which increases thefrictional force so as to make the pile much more difficult to drive.

DESCRIPTION Accordingly, it is among the objects of the presentinvention to avoid undue noise, to overcome other disadvantages of theprior art, and to provide more effective and efficient pile-drivingoperations.

Other objects of the present invention are to provide a noveladvantageous and effective automatically selfregulating variable-stroke,variable-rate and quietoperating pile driver method and system wherein amassive piston weight is bounced upon a cushion of pressure fluid.

lt is an advantage of a pile driver embodying the present invention thata prolonged downward push or thrust results from the pressurizedfluid-cushioned bouncing action of the massive piston weight assembly.This prolonged downward push or thrust is more effective and moreefficient than the conventional sharp hammer-type blow resulting fromimpact of a solid mass against an anvil. This prolonged downward push orthrust is less damaging to the pile driver and to the pile than thesharp hammer-type blow ofa solid mass against an anvil which is typicalof many prior art pile drivers.

Among the advantages of the present invention in certain of its aspectsis that the pile driver embodying these aspects of the invention isadapted for operation in five different modes: (1) solely double-acting,(2) single-acting automatically converting to double-acting at themaximum stroke travel, (3) only single-acting, (4) pre-stressing plusimpacting plus thrusting mode, and (5) in a pile extraction mode.

Among the advantagesprovided by the pile driver methods and systemsembodying the present invention are those resulting from the fact thatin the single-acting mode when the pile being driven encounters softerstrata in the earth, the stroke of the piston weight automaticallyshortens while the number of bounces per minute automatically increase,thus increasing the rate of the quiet powerful bounce thrusts fordriving the pile faster. When harder strata areencountered, the pistonweight automatically bounces higher providing a longer stroke with fewerbounces per minute, thus increasing the force of each quiet powerfulthrust for overcoming the increased impedance being encountered.

In the double-acting mode, when harder strata are I I the presentinvention, can be equipped with a muffler housing surrounding the portsthrough which the expanded pressure fluid is released to muffle thesound of the escaping pressure fluid, such as air or steam. The muffleralso can be used to separate lubricating oil from the released fluid.

Among the further advantages provided by the present invention is thatthe quiet, powerful driving thrust applied to the top of the pileendures for a longer period of time during each driving bounce, anddestructive forces on the pile are substantially reduced as compared toa prior art impact-type pile driver providing a comparable driving rate.

In accordance with one aspect of-the'present invention, there isprovided a controlled release of pressure applied to the pile. Thepressurized driving fluid is released into the bounce chamber from adriving energy chamber. This driving energy chamber is positionedclosely adjacent the bounce chamber, and it is adapted to communicatedirectly with the bounce chamber when a release valve is actuated by thepiston weight. Moreover, the piston weight is re-accelerated upwardly,in a bounce by a cushion of the pressure fluid, thereby providingfurther extension in time of the useful driving thrust, thereby drivingpiles in an effective and efficient method.

in accordance with the present invention, there is a self-regulatingdistribution of the driving energy between the bouncing massive pistonweight and the cylinder bottom assembly which is coupled to the pile.When the pile is being driven through relatively soft material,affording low impedance to the penetration of the pile, the injectedpressurized fluid in the bounce chamber is able to push the cylinderbottom assembly downwardly a greater distance. Thus, during the bounce,there is an increased relative expansion of the pressurized fluiddownwardly and a corresponding decreased relative amount of expansionthereof up wardly as the pressure fluid in the bounce chamberreaccelerates the massive piston weight upwardly. There is a lessresultant upward velocity of the piston weight, and its stroke (ortravel) is correspondingly relatively short. In the single-acting mode,this short stroke provides a relatively rapidcycle time as compared to alonger stroke.

When harder strata are encountered by the pile, affording a greaterimpedance to its penetration, the pressurized fluid in the bouncechamber pushes the cylinder bottom assembly downwardly a shorterdistance. Thus, during the bounce, there is a decreased relativeexpansion of the pressurized fluid downwardly. A corresponding increasedrelative amount of upward expansion of the fluid occurs as itre-accelerates the piston weight upwardly. The result is that there isincreased upward velocity of the piston weight. Accordingly, its strokeis increased so that it goes higher in the upper cylinder. lt therebyaccumulates'more potential energy to beapplied to driving the pileduring the next bounce to provide a more powerful thrust. This increasein driving thrust occurs for both the single-acting or double-actingmodes. The foregoing two paragraphs explain my theory of theself-regulating distribution of the driving energy between the bouncingmassive piston weight and the cylinderbottom assembly, as occasioned bythe impedance being encountered by the pile.

In addition, it is noted that the energy provided by. the injectedpressurized fluid is effectively utilized because the portion of thisenergy which was not used to drivethe pile is employed to re-acceleratethe piston weight upwardly at an increased velocity. Thus, this portionof the energy is substantially conserved (minus friction and heatlosses) by being converted into increased potential energy to beutilized to provide a more powerful thrust on the next bounce.

The deceleration and re-acceleration of the massive piston weighteffectively utilizes not only the force applied in decelerating thepiston weight at the end of its downward stroke, but also effectivelyutilizes the reaction to the re-accelerating force applied to the pistonweight during the period of time such force is being apresulting drivingmode on the pile is to pre-stress the pile, then impact, then thrust itdown. The pre-stressing occurs while the cushion of pressure fluid isdecelerating the piston. This pre-stressing removes all of the playbetween the cylinder bottom assembly and the pile. Then, when the pistonweight strikes bottom with an' impact, the resulting blow starts thepile moving downwardly. The subsequent re-acceleration of the pistonweight upwardly by the pressure fluid provides an enduring thrust whichcontinues to push the moving pile down further.

in the presently preferred embodiment, the cylinder bottom assemblyincludes a second piston located below the bounce chamber in which thepressure fluid operates. This second piston is coupled to the pile beingdriven to transmit the quiet powerful bounce thrusts to the pile, movingin accordance with the pile motion. A driving energy pressurized fluidchamber is associated with this second piston and a valve mechanisminjects a quantity of the pressure fluid automatically from the drivingenergy chamber into the bounce chamber. A self-regulating driving actionoccurs as explained above to seek'the most effective driving action frommoment-to-moment as the pile encounters different strata.

An advantageous self-contained lubrication system is actuated by thepressure impulses in the bounce .chamber.

A muffler housing surrounds the ports through which the expandedpressure fluid is discharged into the atmosphere to muffle the sound ofthe flow of fluid. This muffler also serves to separate the lubricatingoil from the discharged fluid so as to recapture the lubricating oil.This-recaptured oil is returned to the self-contained lubricating systemfor re-use therein.

Additional advantages flowing from this invention are simplicity andreliability of design and construction of the pile drivers with very fewmoving parts.

The pressure fluid utilized can be compressed air or steam or any othersuitable pressurized gas'or vapor. As

used herein, the term pressurized fluid or pressurefluid is intended toinclude compressed air, steam or other suitable pressurized gas orvapor. In the illustrative embodiments shown, it is my preference toutilize compressed air as the pressurized fluid to operate the piledriver.

The various features, aspects and advantages of the automaticallyself-regulating variable-stroke, variablerate and quiet operating piledriver method and system of the present invention will become more fullyappreciated from a consideration of the following detailed descriptionin conjunction with the accompanying drawings, in which:'

FIG. 1 is a side elevational view of a pressure fluid actuated piledriver system embodying the present invention, shown on greatly reducedscale from actual.

size;

FIG. 2 is a cross-sectional view taken along the line 2-2 in FIG. 1 asseen looking downward, being shown on a slightly larger scale than FIG.1;

FIG. 3 is a vertical axial sectional view, shown somewhat furtherenlarged, with the massive piston weight being shown descending andcoming into contact with the control valve actuator;

FIG. 4 is a partial cross-sectional view taken along the line 4-4 inFIG. 3 as seen looking downward;

self-actuated lubrication pump for supplying lubricating oil to themoving parts of the pile driver. FIG. 7 is drawn on a scale ofapproximately onehalf actual size;

FIG. 8 is an elevational sectional view of the inlet arrangement for thepressurized fluid, with the connection for injecting the lubricating oilinto the pressure fluid being shown;

FIGS. 9, 10, 1 1, 12, 13 and 14 are vertical axial sectional viewssimilar to FIG. 3, but shown on somewhat smaller scale than in FIG. 3.These FIGS. 9, 10, 11, 12, 13 and 14 show the successive operatingpositions of the few moving parts of the pile driver system occurringduring one cycle of'operation for delivering a powerful push or thrustto the pile being driven. It is noted that the operating positions shownin FIG. 3 are intermediate those shown in FIGS. 9 and 10;

FIG. 14 shows the massive piston weight being operated in thedouble-acting mode;

FIG. 15 is a vertical axial sectional view of the upper portion of thepile driver, with the operation being in the single-acting mode;

FIG. 16 is similar to FIG. 15, except that the operating modeissingle-acting converting to double-acting at maximum stroke travel asshown;

FIG. 17 is a side elevational view of the pile driver operating in theextraction mode with a pressure fluid cylinder and piston included inthe suspension line for limiting the maximum load applied to thesuspension equipment, such as a crane, and for isolating the suspensionfrom the jarring effects of the pile driver when acting in theextraction mode;

FIG. 18 is a side elevational view and partial sectional view as seenalong the line l8l8 in FIG. 17;

FIG. 19 is an elevational sectional view of the pile driver adapter andconical guide used for driving wooden piles;

FIG. 20 is a vertical axial sectional view showing a modified embodimentof the invention; and

FIG. 21 is a vertical axial sectional view of another embodiment.

With reference to FIGS. 1-4, an automatically selfregulatingvariable-stroke, variable-rate and quiet operating pile driver methodand system 20 are shown embodying the present invention. The pile driversystem 20 comprises a cylinder wall 22 surrounding a cylinder 23provided with a massive piston weight assembly, generally indicated at24 (See FIG. 3). At the lower end of the cylinder wall 22 is a cylinderbottom assembly, generally indicated at 26, effectively closing off thelower end of the cylinder wall 22..The cylinder bottom assembly 26'iscoupled to the pile 28 being driven by a detachable coupling 30 and apile-driving adapter 32 which is shaped so as to engage the upper end oftheparticular pile being driven.

When it is desired to drive a pile having a different size or adifferent configuration (such as pipe pile, H- beam pile, timber pile)then the coupling 30 is temporarily disconnected, and a differentadapter 32 is inserted for providing the desired engagement with thepile. A pipe pile 28 is shown in FIGS. 1 and 3, but this is illustrativeonly. It is to be understood that the present invention can be used toadvantage for driving any type of drivable pile.

There is a bounce chamber 34 (FIG. 3) which is located within thecylinder wall 22 between the lower end of the massive piston weightassembly 24 and the cylinder bottom assembly 26. Pressure fluidinjection means 36 are provided for suddenly injecting pressurized fluidinto the bounce chamber 34 beneath the descending piston weight assembly24. This fluid injection means 36 includes a pressurized driving fluidstorage chamber 38 and a control valve mechanism 40 which communicateswith the bounce chamber 34.

The massive piston weight assembly 24 moves up and down within thecylinder 23, and it bounces upon a cushion of pressurized fluid in thebounce chamber 34. The manner in which the pressurized fluid is injectedinto the bounce chamber, and the many advantages which accrue from theadvantageous massive piston bouncing action are indicated in theintroduction and will be described further below.

The massive piston weight assembly 24 includes a main weight 42 ofsuitable massive and strong material. For example, in this illustrativeembodiment, the main weight 42 is a solid steel member of generallycylindrical configuration with bearings, piston rings and end capsattached to its lower and upper ends. Its lower and upper ends areidenticalin construction, and so only the lower end is shown in detailin FIG. 3 in order to simplify and clarify the drawings. If it isdesired to see the upper end of the piston weight assembly 24, it isnoted that this can be seen in FIGS. 2, l4, l5, and 16.

Referring particularly to FIGS. 3 and 7, it is seen that a bearingsleeve member 44 is mounted on each end of the mainweight 42. Thissleeve member 44 has an annular configuration and fits onto a reduceddiameter end portion 46 at the end of the weight 42, abutting against anannular shoulder 48. This bearing sleeve member 44 isformed' of suitablebearing material to run against the cylinder wall22, for example, it isformed of bearing bronze. It is retained by an end cap I 50 of toughhardened steel secured to the weight 42 by detachable fastening meansshown as machine screws 52.

In order to form a fluid seal near the end of the-piston weight assembly24, a plurality of piston rings 54 are provided. These piston rings 54aremounted in an annular gland member 56 which is retained by the endcap 50 together with the bearing sleeve 44. There is a substantialannular clearance space 58 provided beneath the gland 56, so that itcan: move to accommodate any relative sideward movement of pistonassembly 24 relative to the cylinder wall 22. In other a plurality ofwords, the relatively movable or floating" gland 56 provides the rings54 with accurate firm support, because the floating action of the gland56 prevents it from wearing against the cylinder wall during the up anddown motion of the massive piston weight 24. In this way any side thrustwhich occurs is caused to be borne by the bearing member 44, and whenthe bearing member 44 wears, there remains a very small clearancebetween the floating gland 56 and the cylinder wall. Thus, the pistonrings continue to be well supported to last a long time. The way inwhich the piston rings and gland are assembled is that the piston ringsare split so as to be inserted into the grooves in the annular gland;whereas the gland 56 itself has a continuous circular configuration andis placed adjacent to the bearing sleeve 44 before the end cap 50 issecured in place. There is a close fit between the end cap 50 and thelower radial surface of the gland member 56 and also a close fit betweenthe bearing member 44 and the adjacent upper radial surface of the glandmember. Thus, an effective fluid seal is provided by the piston rings 54and the gland 56 even though there is a large clearance space 58 beneaththe gland.

In my presently preferred illustrative embodiment as shown, the cylinderbottom assembly 26 includes a second piston 60. This second piston 60 isadapted to move up and down for a limited travel distance within asecond cylinder 61 which is defined by a lower extension of the cylinderwall 22 below the level of the bounce chamber 34. To retain the piston60 within the cylinder 61, there is an annular stop shoulder 63surrounding the piston 60. An annular retainer and bear ing element 65defines the lower end of the cylinder 61. The retainer and bearingelement 65 is secured by large machine screws 67 to a mounting ring 69which is welded to the exterior of the cylinder wall 22. At the lowerend of the piston 60, there is a coupling flange 71' adapted to begripped by the detachable coupling 30. The detachable coupling 30 isformed by two semi-circular clamps with protruding mating flanges 73which are secured together by bolts 75.

As an alternative embodiment shown in FIG. 21, it is noted that thecylinder bottom assembly 26 can be The driving fluid chamber means 38 islocated within the second piston of the cylinder bottom assembly 26. Thechamber bore 64 is lined by a cylinder sleeve 66. A bottom flange 68 ofan upstanding valve stem guide lines the bottom of the driving fluidchamber 38. The guide 70 has a bore 72, and a valve stem 74 of valvemember 76 extends into this bore 72. The valve member 76 has a conicalvalve surface 78 which seats upwardly against a conical valve seat 80formed in the end cap 82 of the second piston 60. This second piston isprovided with a bearing sleeve member 84, piston rings 86 and an annulargland 88 having annular clearance 58 similar to those elements for bothends of the piston weight assembly 24.

In order to actuate the valve mechanism 40 by the piston weight 24,there is an upwardly extending actuator 91 integral with the valvemember 76. The actuator 91 is equipped with pressurized fluid trappingmeans 93 in the form of an enlarged cylindrical'plunger. This plunger 93can be depressed to fit snugly into the port 62 to trap pressurizedfluid in the bounce chamber 34.

When the valve member 76 is depressed away from its valve seat 80,pressurized fluid in the driving fluid chamber 38 can rush up throughmultiple channels (FIG. 4) to bypass the perimeter of the valve member76 so .as to be injected through the port 62 into the bounce chamber 34.The channels 90 are formed by grooves between lands 92 in the interiorof the cylinderical liner 66.

The pressurized fluid is supplied from a suitable source, for example,such as the pressure storage tank (not shown) of an air compressor (notshown). The compressed air is at a suitable pressure of, for example, 80pounds per square inch (p.s.i.) to 3,000 p.s.i.

I When the valve member 76 is depressed, its annular groove 95 (FIG. 3)cooperates with the upper end of the valve guide 70 (as seen in FIG. 12)to act as resilient'deceleration means by trapping fluid in the groove95. This trapped fluid provides resilient deceleration for the depressedvalve member to defined by a closed lower end ofthe cylinder 22. In

other words, in such an alternative embodiment, the

second piston 60 is replaced by a fixed member 60A I which is welded orotherwise attached to the lower portion of the cylinder wall 22, so asto be effectively integral with the cylinder wall 22.

It is my present preference to utilize a cylinder bottom assembly 26which includes a relatively movable second piston 60, because'the use ofthis second piston 60 de-couples the cylinder wall 22 from the pile 28.

This de-coupling of the cylinder wall 22 from the pile 28 reduces theamount of mass to be driven downwardly when the powerful driving thrustis applied to drive the pile 28.

As explained above, the fluid injection means 36 includes the drivingfluid chamber 38 and the control prevent its banging down on the guide70.

The pressurized fluid is fed to the pile driver system 20 through aflexible pressure hose line 94 and through a connection fitting 96. Thisfitting 96feeds into an input passage 98 which communicates with thebore 72 of the valve stem guide 70. The pressurized fluid from the bore72 flows through a constricted passageway 100 into the driving fluidchamber When the valve stem 74 is in its uppermost position as shown inFIG. 3, the pressurized fluid can also flow through a less restrictedpassageway 102 into the chamber 38. The two passageways 100 and 102 arein parallel flow relationship; the lower constricted one 100 is alwaysopen, but the upper unrestricted one 102 is shut off when the valvemember 76 together with its stem 74 is depressed by the piston weight24.

After the piston weight 24 has bounced upwardly from the cushion ofpressurized fluid, as shown in FIG. 13, the expanded pressure fluid 104is released from the cylinder 23 through a plurality of outlet ports 106in the cylinder wall 22. The outlet ports 106 communicate with anannular muffler chamber 108 defined by a removable muffler housing 109which includes a pair of spaced cylindrical walls 110 and 112. Themuffler housing walls 110 and 112 are rigidly interconnected by a bottomring plate 114 (FIG. 3) which is detachably secured to a mounting ring116 by a plurality of bolts 118. The mounting ring 116 is secured to theoutside of the cylinder wall 22 by welding.

Shown in FIGS. 5 and 6 is the upper end of the removable muffler 109.The annular muffler chamber 108 communicates through multiple ports 120with a quantity of oil air separating material 122 in the top of anannular muffler chamber 123 (please see also FIG. 3) for separatingdroplets of lubricating oil from the expanded pressure fluid 104 afterpassing through the ports 120. The material 122 is coarse stainlesssteel wool matting. A removable cover 124 secured by screws 126 enablesthe oil separating material 122 to be removed and replaced. I

The expanded pressure fluid 104 flows down through the material 122,then down through the multiple holes 127 in a material support ring 129,and as shown in FIG. 6, the fluid 104 then flows into an inverted U-shaped fluid outlet baffle 128. The interior of the baffle 128communicates with an atmospheric vent 130 through which the expandedpressure fluid passes out into the atmosphere. The purpose of the baffle128 is to prevent the separated oil droplets from being blown out intothe atmosphere.

As shown in FIG. 6, the separated oil droplets 132 fall from theseparation material 122 in the chamber 123; and as shown in FIG. 3, thisoil collects in an annular reservoir 134 at the bottom of the chamber123. Thus, an oil reservoir is provided'for the self-containedlubrication system which will be explained further below.

The muffler housing 109 can be removed to provide access to the ports106, if desired, by unscrewing the bolts 118 (FIGS. 3 and 7). As shownin FIG. 6, the top of the muffler housing 109 has an O-ring seal 136 forsealing the muffler chamber 108. Thus, the seal 136 can be slid up alongthe exterior of the cylinder wall 22 for removing the muffler housing109. With reference to FIG. 1, the mounting 138 for the lead guides andthe upper muffler and air filter 140 can be removed so as to permitcomplete removal of the muffler housing 109, if desired.

The self-contained lubrication system is shown'in greatest detail inFIGS. 7 and 8. The level L (FIG. 3) of the oil in the reservoir 134 canbe seen by observing an oil 'gauge 135 having a transparentnon-breakable plastic tube. Oil from the reservoir 134 can flow downthrough an oil supply passage 142 into an inlet passage 144 sealed by aseal 145 .and communicating with the inlet chamber 146 of an oil filterassembly 150. An annular filter cartridge 148 of filter material such asfelt separates the inlet chamber 146 from an outlet chamber 152 throughwhich passes the end cap retainer bolt 154. The filter element 148 canbe removed and replaced by unscrewing the bolt 154 and up to an oil hole172 (FIG. 1) for dispensing lubricating oil above the piston weightassembly 24 to lubricate the piston 24 and cylinder wall 22.

The other feed line 159 feeds through a check valve 174 into ahigh-pressure pump chamber 176 containing a smaller diameter piston 178.This piston 178 pumps oil under high pressure through a check valve 179into an oil line 180 extending down to a swivel 182 (FIG. 8) on theinlet connection fitting 96 for the pressurized fluid. The swivel 182has a passage 183 and an annular channel 184 for feeding oil inwardthrough a pair of oil holes into the bore 97 of the fitting 96.

Thus, the lubricating oil is mixed with the incoming pressurized fluid,and thereby oil is dispensed up through the passage 98 so as tolubricate the fluid injection means 36 including the 'valve mechanism40. This oil entering through the passage 98 also serves to lubricatethe bounce chamber 34, the piston 60 and the cylinder wall 22surrounding the piston 60.

Inviting attention again to FIG. 7, it is noted that pistons 166 and 178are connected together to form a double piston. A spring 186 in thelow-pressure pump chamber 164 urges both pistons 166 and 178 toward theleft. In other words, the spring 186 urges the pistons 166 and 178 inthe direction of their intake stroke. The high pressures occuring in thebounce chamber 34 are utilized to drive the pistons 166 and 178 towardthe right, i.e. in the direction of their expulsion (pumping) stroke. Asmall port 188 in the cylinder wall 22 communicates through drilledpassages 189 in a base plate 190 with a passage 192 leading into thepiston-actuating chamber 194.

The base plate 190 serves to support both the oil filter assembly 150and the oil pump 160. This base plate 190 can be detached from theoutside of the' cylinder wall 22. As shown in FIG. 3, this base plate isremovably secured by machine screws 196 (only one can be seen .in FIG.3).'

When driving a pile, as shown in FIGS. 1' and 2, the pile driver systemis guided by a pair of spaced parallel vertical guide rails 200 and 201,which are called leads. The use of leads is well known in the art ofdriving piles, and their usage is not claimed as novel.

These leads are engaged by lower and upper guides 204 p .ing clamp ring138 surrounding the cylinder wall 22.

The upper clampring 138-is formed in two semi-circles with protrudingmating flanges 213 secured together by bolts 214.

In order to allow atmospheric air to flow in and out of the upperportion of cylinder 23 above the piston weight 24, there are provided aplurality of vent ports 216 (FIG. 15) communicating with an annularmuffler and air filter housing 140. This housing defines inner and outerannular muffler chambers 218 and 220. FIG. 15 shows the atmospheric air222 being expelled from the cylinder 23, because the piston weight 24 isrising. It will be understood that as soon as the piston 24 beginsdescending again, the atmospheric air will be sucked back into thecylinder 23. To exclude dust and dirt there is an air filter element 224in thechamber 220 adjacent to the atmospheric vent 226.

In order to provide various driving modes for the pile driver system 20,various sizes of head plugs 230 (FIG. 230A (FIG. 1) are utilized. Thehead plugs are removably secured in the top of the cylinder wall 22, bydetachable fastening means 232 shown as machine screws. The deep headplug 230A shown in FIG. 1 extends down so far that it blocks the ventports 216, thus producing the double-acting driving mode, as will beexplained in detail further below.

The shallow head plug shown in FIG. 15 produces a single-acting drivingmode.

When the piston weight assembly 24 makes extreme upward excursionswithin the cylinder 23, as shown in FIG. 16, then the single-actingdriving mode automatically converts to a double-acting mode.

In use, the pile driver system (FIG. 1) or 20A (FIG. 20) or 208 (FIG.21) can be supported by a cable 236 (FIG..1) from a suitable crane (notshown) attached to suitable support means (234), such as connectionmeans attached to the upper end of the pile driver, for example, to thehead plug 230 or 230A.

When used in the pile-extraction mode, as shown in FIGS. 17 and 18, thesupport cable 236 can advantageously be fastened to connection means 238attached to a pressure-fluid cylinder 240 having a piston 242 thereinwith a chamber 244 below the piston. The piston rod serves as supportmeans 234 attached to the upper end of the pile driver. Pressurizedfluid, for example, such as compressed air or other gas under pressure,is supplied from a pressurized fluid source 246, such as'the receiver ofan air compressor. This pressurized fluid is supplied through anadjustable pressure regulator 248 into the cylinder chamber 244.

The regulator 248 is adjusted by the operator such that the totalforce-developed by the pressurized fluid in the chamber 244 actingupwardly upon the working area of the piston 242 is moderately less thanthe safe maximum'lifting load of the crane pulling on the cable 236.

It will be understood that when acting in the pile-extraction mode (asshown in FIGS. 17 and 18) a large upward pull is being exerted by thecable 236, and the pile driver is. arranged to deliver jarring upwardblows so as to extract the pile 28. Thus, by regulating (248) thepressure, the fluid cylinder and piston 240, 242, 244 serve as overloadprotection means for the crane (or other lifting means being used).Also, this fluid cylinder and piston serve as mechanical shock absorbermeans, because the'fluid (air or gas) in the chamber 244 iscompressible'and serve as a resilient support. In this way the cable 236and crane or other lifting means are spared from experiencing the wearand tear which jarring action of the ward thrust on the pile driverduring each stroke of the piston weight 24. If desired, the upper endcap 50 of the reciprocating piston weight 24 can be arranged to strikeup against the head plug 230 to exert an upward impact for jarring thepile loose. This upward striking is accomplished by installing a headplug which extends down to the level of the vent ports 216.

The upward pull of cable 236 (FIG. 17) on the pile driver causes theannular shoulder 63 (FIG. 18) of the second piston 60 to engage theretainer stop and bearing element 65. There is a loose coupling250 whichis connected by the coupling 30 to the cylinder bottom assembly 60. Thisloose (or overriding) coupling 250 permits downward motion of thecylinder bottom assembly 60 without imposing any downward thrust on thepile 28. However, the upward thrust occurring at the peak of each upwardstroke of the piston weight 24 is transmitted by the coupling 250 to thepile 28 being extracted.

As an example, the pile 28 (FIGS. 17 and 18) is shown as an H-beam pile,but other types of piles can also be extracted with advantage by use ofthe invention.

The loose coupling 250 is shown as including a cylinder having anabutment 254 at its lower end. An extractor rod 256 is attached to thepile 28 being extracted. A head 252' on this rod strikes against theabutment 254 for delivering upward thrusts to the pile for extractingit.

FIG. 19 shows the pile driver system 20 (FIG. 1) or 20A (FIG. 20) or 208(FIG. 21) being used for driving a timber pile 28. A conical guide 258is shown for centering the pile driver 20, or 20A, or 208 upon thetimber pile 28. The guide 258 is secured by a clamp to an attachmentgroove 260 (See also FIG.;3) in the pile adapter 32.

With reference to FIG. 20,-a modified pile driver system 20A is shownembodying the invention and adapted for practicing the method of theinvention. The only change from .the pile driver system and method 20,as described above, is that the valve actuator 91A does not includefluid-trappingmeans in the form of an enlarged head such as shown at 93(FIG. 3).

Thus, in FIG. 20, when the piston weight assembly 24 descends, it isdecelerated by the pressure fluid in the bounce chamber and thereafterforces this fluid back down into the driving fluid storage chamber 38.Impact at reduced velocity is thereby allowed to occur between thepiston weight 24 and the second piston 60. Thereafter, the piston weight24 is re-accelerated upwardly by pressure fluid released by open'valve40 from the driving fluid chamber 38.

Accordingly, it will be understood that FIG. 20 is well adapted toprovide the fourth mode set forth in the introduction, namely,pre-stress plus impact plus thrust. The pre-stressing occurs while thecushion of pressure fluid injected into the bounce chamber by the valvemeans 40 plus any residual fluid in the bounce chamber is deceleratingthe piston weight. This prestressing removes all of the play between thesecond piston 60 and and the pile 28. Then, when the piston weight 24strikes the second piston 60 with an impact, as shown in FIG. 20, theresulting blow starts the pile moving downwardly, as indicated by thetwin arrows near the coupling 30 in FIG. 20. Following impact, there isa powerful thrust delivered to the moving pile to keep it moving down ina highly effective driving mode. This powerful enduring thrust isdelivered to the pile during the re-acceleration of the piston weightupwardly.

There is an advantageous method for increasing or decreasing the amountof impact occurring in the system A of FIG. 20. The actuator 91A islengthened to decrease the amountof impact and is shortened to increasethe amount of impact. This lengthening or shortening is accomplished byremoving the valve member 76 and replacing it with one having a longeror shorter actuator 91A, as desired.

When a longer actuator 91A is employed, the valve 40 is opened to injectthe pressurized fluid beneath the descending piston weight 24 when it isfarther from the cylinder bottom assembly 60. The pressurized fluidthereby has a longer time to act and thus decelerates the piston weight24 toa slower velocity before impact occurs, producing a reduced impact,and vice versa.

If a sufficiently long actuator 91A is employed, then impact will notoccur, provided that the fluid driving chamber 38 is sufficiently largeto adequately fill the bounce chamber with pressurized fluid at asufficient pressure to completely decelerate the piston weight in thetime available.

This pre-stress plus impact plus thrust driving mode can be used toadvantage for driving very stubborn piles. The amount of impact can beadjusted, in the manner explained above, so as to start the pile moving.Then the pile driver provides a powerful, enduring thrust to push themoving pile on down further in an effective efficient operation. Theamount of impact can be just sufficient to start the pile moving, beingvery effective because the pile is already pre-stressed. Thus,excessiveimpact as occurs in the prior art is avoided. The powerful,enduring after thrust is very effective because it is delivered to analready moving pile.

With reference to FIG. 21, another modified pile driver system 20B isshown embodying the invention and adapted for practicing the method oftheinvention. The only change from the pile driver system and method 20,is that the cylinder bottom assembly 60A in the system 20B is securedto'the lower end of the cylinder wall 22. This cylinder bottom assemblyis attached by a large number of strong machine screws 262. Thisattachment is an advantage because it reduces the number of moving partsin the pile driver system to two, namely, the piston weight assembly 24and the valve member 76. (In counting the moving coupling the mass ofthe cylinder wall 22 (together with everything rigidly attached to thewall 22) from the pile being driven, thus making the driving jobcorrespondingly easier. However, in certain pile driving applications,the advantage of fewer moving parts may outweigh the advantage ofreduction of the effective mass being driven.

14 FURTHER ASPECTS OF OPERATION as the case may be. Thus, the valveactuator 91 or 91A is depressed so that the valvemember 76 is spacedfrom its seat. There is a modest clearance around the enlarged head 93so that fluid can leak from the pressure fluid driving chamber 38 intothe bounce chamber 34. There is large clearance around the actuator 91Aso that the pressurized fluid can flow from chamber 38- into the chamber34.

The person who is using the pile driving systems 20,

20A or 208, starts operation by suddenly opening up a shut-off valve(not shown) to begin supplying pressurized fluid though the hose line94. The driving pressure fluid storage chamber 38 is now supplied withpressurized fluid through the constricted-passage 100 (FIG. 3). (Largepassage 102 is now blocked by the stationary depressed stem 74.)

In the system 20 or 20B, the pressurized fluid enters the bounce chamberby leaking through the clearance around the plunger head 93. The pistonweight 24 is raised up by the entering fluid, and the pressure fluid inthe bore 72 acts on the stem 74 to cause the valve member 76 to move uptogether with the piston weight 24. When the head 93 leaves the injectorport 62, the accumulated pressure fluid in the chamber 38 rushes up intothe bounce chamber 34 to suddenly push the piston weight up. The valvemember 76 rises up against its seat to close the valve 40. The passage102 is unblocked because the stem 74 has moved up. Thus, the

pressure fluid now rushes through both passages and l02, so that thepressure in chamber 38 is raised up substantially to the supplypressure.

In the pile driver system 20A of FIG. 20, the operator starts the pistonweight. 24 in the same way as for systems 20 and 20B, namely, bysuddenly starting the flow of pressure fluid through the line 94. Thepassage 100 allows pressure fluid to surge into the storage chamber 38,and it flows up through the open valve-40. This surge of pressure fluidup through the open'va'lve 40s uddenly pushes the piston weight 24upwardly.

The sudden upward push on the piston weight 24 (in systemv 20, 20A, or208) causes it to rise up, as shown in FIG. 13, to the point where theoutlet ports 106 are unblocked. The expanded pressure fluid-in thebounce chamber 34 is released through ports 106, allowing the pistonweight 24 to fall, as shown in FIG. 9. When the piston weight strikesthe actuator 91, as shown in FIG. 10, the valve 40 is suddenly opened toinject pressure fluid from the storage chamber 38 into thebounce chamber34. This second injection of the pressure fluid is greater than thefirst one, because the pressure in storage chamber 38 has become moreearly equal to supply pressure. Thus, the piston weight 24 is accelerated more and rises up, as shown in FIG. 13, further beyond theports 106.

. in FIGS. 9, l0, 11, 12, 13 and 14, when the piston weight hasreachedits full amplitude, in eachcycle it descends so far that theplunger head 93 is driven down to block the port 62, as shown in FIG.11.

The following is an explanation of a typical operating cycle: FIG. 9shows the piston weight 24 descending. It

is below the level of the outlet ports 106, and so any residual pressurefluid in the bounce chamber 34 is being compressed. This compressionbegins to decelerate the piston weight, and the'compression also beginsto exert a downward thrust on the cylinder bottom assembly 26, therebybeginning to thrust down upon the pile 28. In this way, the bottomassembly 26, coupling 32, and pile 28 are prestressed to remove all playtherein.

FIG. 3 shows the piston weight assembly at the moment it comes incontact with the head 93 of the actuator 91.

.FIG. 10 shows the valve fully opened by depression of the actuator. Thepressure fluid is being injected through the port 62 into the bouncechamber. The resultant sudden increase in pressure beneath the pistonweight 24' increases its deceleration and produces a powerful downthruston the pile 28, as indicated in FIG. 10 by the twin arrows on theadaptor 32. v

' .FIG. 11 shows the injection port 62 closed by the fluid trapping headmeans 93. The injected pressure fluid and any residual pressure fluidremaining in the bounce chamberfrom the previous cycle are now trappedby blockage of the port 62. Accordingly, the

descending piston weight produces a tremendous compression of thetrapped fluid, as indicated by the compression arrows C (FIG. 11) andstill greater compressionC' (FIG. 12).

The increasing compression pressures (C and C) produce a tremendous andenduring downward thrust on the pile, as'show'n by the twin arrows inFIGS. 11

and 12 near the coupling 30. A resilient compressed fluid cushionedbouncing action occurs, i.e. the piston weight .is completelydecelerated and is re-accelerated upwardly, as shown in FIG. 13.

The re acceleration upwardly, such as occurs between FIGS. 12 and 13,produces a continuing powerful downward'thrust on the 106 are uncovered.I

Thus, there is a downward thrust occuring during the operation shown inFIGS. 9, 3, 10,11 and 12 and during the re-acceleration occuring betweenthe positions pile until the ports shown in FIGS. 12 and 13.

head plug.

' It is noted that a two-stage trapping action of compressible fluidoccurs beneath the descending piston in a cable 236 (FIG. 17), so thatthe pile driver 20 is resting I down upon the pile, then the flow ofpressure fluid is turned on in the line 94 to-start the piston weight upand down. As soon as it is reciprocating at full amplitude, the upwardpull is applied to the cable 236 to begin extraction. 7

In all of the systems shown, the reciprocation of the piston weight 24is stopped byshutting off the flow of pressure fluid through the hoseline 94.

The pile driver system 20A or 20B can also be used for pile extractionin the same general manner as the pile driver system 20.

Advantageously, the operator can increase the time duration of eachfluid-cushioned powerful driving thrust and, decrease the peak forceoccuringduring each driving thrust by increasing the extent of trappingof pressurized fluid by the trapping means 93 (FIG. 3), and vice. versa.By increasing the height of trapping means 93, port 62 becomes blockedwhen piston 24 is at a larger predetermined distance from the bottomassembly 26, thus increasing the extent of trapping, and

vice versa. For convenience, if desired, detachable the bottom assemblyinjecting pressurized compressible fluid into the region between thedescending piston weight and the bottom assembly to decelerate thepiston weight and to re-accelerate it upwardly within the cylinder witha sudden fluid-cushioned bouncing action for providing a powerful,fluid-cushioned thrust acting down upon said bottom assembly to betransmitted to the pile during the deceleration and re-acceleration 0fthe piston weight, releasing the expanded pressure fluid from thecylinder, and again producing a descending motion of the piston weightwithin the cylinder, and repeating the steps to provide a sequence ofpowerful, fluid-cushioned thrusts acting down upon said bottom assemblyto be transmitted to the pile for effectively driving the pile into theearth.

2. The method of driving a pile into the earth, as claimed in claim 1,in which the step of providing a cylinder having a bottom assemblyincludes thestep of decoupling the cylinder bottom assembly from thecylinder for effectively reducing the mass to be driven.

3. The method of driving a pile into the earth, as claimed inclaim 1,including the step of trapping atmospheric air above the upwardly movingpiston weight for providing a double-acting effect.

4. The method of driving a pile into the earth, as

. claimed in claim 1, including the step of temporarily trappingthe'injected pressurized. fluid between the descending piston weight andthe cylinder bottom assembly for preventing the massive piston weightfrom impacting against the bottom assembly.

- between the descending piston weight and the cylinder 'bottom assemblyfor shortening the time duration of each powerful fluid-cushioneddriving thrust acting upon the pile and increasing the peak forceoccuring during each driving thrust.

7. The method of driving a pile into the earth, as claimed in claim 1,including the step of permitting the decelerated piston weight to impactagainst the cylinder bottom assembly to produce a blow followed by adownward thrust occuring as the piston weight is re-acceleratedupwardly.

8. The method of driving a pile into the earth, as claimed in claim 7,including the step of increasing the predetermined distance above thebottom assembly at which thepressurized fluid is injected for increasingthe deceleration of the descending piston weight, thereby to reduce theamount of impact of the piston weight .against the bottom assembly.

ing the pile into the earth.

9. The method of driving a pile into the earth, as

claimed in claim 1, including the steps of providing a storage chamberfor compressible pressurized fluid near the cylinder and supplyingpressurized fluid into the storage chamber, and injecting thepressurizedfluid from said storage chamber into said region between the descendingpiston weight and the bottom assembly.

10. The method of driving a pile into the earth, as

' claimed in claim 9, including the steps of causing the firstpredetermined distance from the bottom assembly trapping compressiblefluid within the cylinder between the descending piston weight and thebottom assembly to begin decelerating the descending piston weight, whenthe descending piston weight reaches a second predetermined distancefrom the bottom assembly injecting pressurized compressible fluidintothe cylinder between the descending piston weight and the cylinderbottom assembly for further decelerating the descending piston weightand to re-accelerate it upwardly with a sudden bouncing action forproviding a powerful thrust to said bottom assembly to be trans- 12. Themethod of driving a pile into the earth comprising the steps ofproviding a cylinder having a bottom assembly coupled to the pile to bedriven, providing a descending motion of a massive piston weighttravelling within the cylinder toward the bottom assembly, when thedescending piston weight reaches a first predetermined distance from thebottom assembly trapping compressible fluid within the cylinder betweenthe descending piston weight and the bottom assembly to begindecelerating the descending piston weight, when the descending pistonweight reaches a second predetermined distance from the bottom assemblyinjecting pressurized compressible fluid into the cylinder between thedescending piston weight and the cylinder bottom assembly to furtherdecelerate the descending piston weight, when the descending pistonweight reaches a third predetermined distance from the bottom assemblytrapping the injected pressurized fluid within the cylinder between thedescending piston weight and the bottom assembly to completelydecelerate the descending piston weight and to re-accelerate it upwardlywith a sudden bouncing action for providing a powerful thrust to saidbottom assembly to be transmitted to the pile during the decelerationand re-acceleration of the piston weight, releasing the expandedpressure fluid from the cylinder for again providing a descending motionof the piston weight within the cylinder, and repeating the steps toprovide a sequence of powerful thrusts to said bottom assembly to betransmitted to the pile for effectively driving the pile into the earth.

13. The method of extracting a pile from the earth comprising the stepsof providing a cylinder having a bottom assembly and providing an upperhead, producing a descending motion of a massive piston weighttravelling down within said cylinder directly toward said bottomassembly, as said massive piston weight is travelling downwardly andbefore the piston weight reaches the bottom assembly injectingcompressible pressurized fluid as defined herein into the region betweenthe descending piston weight and the bottom assembly to prevent saidmassive piston weight from hitting said bottom assembly and to bouncethe piston weight upwardly within the cylinder upon a cushion of saidpressurized fluid, causing the upwardly travelling piston weight toexert an upward thrust against said upper head for producing an upwardjarring action to be transmitted to the pile for extraction thereof,releasing the expanded fluid from beneath the piston weight into theatmosphere for producing another descending motion thereof, andrepeating the steps for producing a sequence of upward jarring actionsfor extracting the pile.

14. The method of extracting a pile from the earth, as claimed in claim13, including the step of trapping atmospheric air between theupwardlytravelling piston weight and the upper head.

15. The method of extracting a pile from the earth, as

claime'd'in claim 13, including the step of causing theupwardlytravelling weight to impact against the upper head.

16. The method of driving a pile into the earth comprising the steps ofcyclically bounding a mass up and down upon a cushion of compressiblepressurized fluid, cyclically injecting additional compressiblepressurized fluid into the cushion beneath the mass during the cycle ofoperation when the mass is moving downwardiy,

cyclically releasing expanded compressible pressurized

1. The method of driving a pile into the earth comprising the steps ofproviding a cylinder having a bottom assembly, producing a descendingmotion of a massive piston weight moving within the cylinder toward thebottom assembly, when the descending piston weight reaches apredetermined distance above the bottom assembly injecting pressurizedcompressible fluid into the region between the descending piston weightand the bottom assembly to decelerate the piston weight and tore-accelerate it upwardly within the cylinder with a suddenfluid-cushioned bouncing action for providing a powerful,fluid-cushioned thrust acting down upon said bottom assembly to betransmitted to the pile during the deceleration and re-acceleration ofthe piston weight, releasing the expanded pressure fluid from thecylinder, and again producing a descending motion of the piston weightwithin the cylinder, and repeating the steps to provide a sequence ofPowerful, fluid-cushioned thrusts acting down upon said bottom assemblyto be transmitted to the pile for effectively driving the pile into theearth.
 1. The method of driving a pile into the earth comprising thesteps of providing a cylinder having a bottom assembly, producing adescending motion of a massive piston weight moving within the cylindertoward the bottom assembly, when the descending piston weight reaches apredetermined distance above the bottom assembly injecting pressurizedcompressible fluid into the region between the descending piston weightand the bottom assembly to decelerate the piston weight and tore-accelerate it upwardly within the cylinder with a suddenfluid-cushioned bouncing action for providing a powerful,fluid-cushioned thrust acting down upon said bottom assembly to betransmitted to the pile during the deceleration and re-acceleration ofthe piston weight, releasing the expanded pressure fluid from thecylinder, and again producing a descending motion of the piston weightwithin the cylinder, and repeating the steps to provide a sequence ofPowerful, fluid-cushioned thrusts acting down upon said bottom assemblyto be transmitted to the pile for effectively driving the pile into theearth.
 2. The method of driving a pile into the earth, as claimed inclaim 1, in which the step of providing a cylinder having a bottomassembly includes the step of decoupling the cylinder bottom assemblyfrom the cylinder for effectively reducing the mass to be driven.
 3. Themethod of driving a pile into the earth, as claimed in claim 1,including the step of trapping atmospheric air above the upwardly movingpiston weight for providing a double-acting effect.
 4. The method ofdriving a pile into the earth, as claimed in claim 1, including the stepof temporarily trapping the injected pressurized fluid between thedescending piston weight and the cylinder bottom assembly for preventingthe massive piston weight from impacting against the bottom assembly. 5.The method of driving a pile into the earth, as claimed in claim 4,including the step of increasing the amount of the injected pressurizedfluid trapped between the descending piston weight and the cylinderbottom assembly for extending the time duration of each powerfulfluid-cushioned driving thrust acting upon the pile and reducing thepeak force occuring during each driving thrust.
 6. The method of drivinga pile into the earth, as claimed in claim 4, including the step ofdecreasing the mount of the injected pressurized fluid trapped betweenthe descending piston weight and the cylinder bottom assembly forshortening the time duration of each powerful fluid-cushioned drivingthrust acting upon the pile and increasing the peak force occuringduring each driving thrust.
 7. The method of driving a pile into theearth, as claimed in claim 1, including the step of permitting thedecelerated piston weight to impact against the cylinder bottom assemblyto produce a blow followed by a downward thrust occuring as the pistonweight is re-accelerated upwardly.
 8. The method of driving a pile intothe earth, as claimed in claim 7, including the step of increasing thepredetermined distance above the bottom assembly at which thepressurized fluid is injected for increasing the deceleration of thedescending piston weight, thereby to reduce the amount of impact of thepiston weight against the bottom assembly.
 9. The method of driving apile into the earth, as claimed in claim 1, including the steps ofproviding a storage chamber for compressible pressurized fluid near thecylinder and supplying pressurized fluid into the storage chamber, andinjecting the pressurized fluid from said storage chamber into saidregion between the descending piston weight and the bottom assembly. 10.The method of driving a pile into the earth, as claimed in claim 9,including the steps of causing the descending piston weight to actuatethe injection of pressurized fluid into said region between thedescending piston weight and the bottom assembly.
 11. The method ofdriving a pile into the earth comprising the steps of providing acylinder having a bottom assembly coupled to the pile to be driven,providing a descending motion of a massive piston weight travellingwithin the cylinder toward the bottom assembly, when the descendingpiston weight reaches a first predetermined distance from the bottomassembly trapping compressible fluid within the cylinder between thedescending piston weight and the bottom assembly to begin deceleratingthe descending piston weight, when the descending piston weight reachesa second predetermined distance from the bottom assembly injectingpressurized compressible fluid into the cylinder between the descendingpiston weight and the cylinder bottom assembly for further deceleratingthe descending piston weight and to re-accelerate it upwardly with asudden bouncing action for providing a powerful thrust to said bottomassembly to be transmitted to pile during the deceleration andre-acceleration of the piston weight, releasing the expanded pressureflUid from the cylinder for again providing a descending motion of thepiston weight within the cylinder, and repeating the steps to provide asequence of powerful, fluid-cushioned thrusts to said bottom assembly tobe transmitted to the pile for effectively driving the pile into theearth.
 12. The method of driving a pile into the earth comprising thesteps of providing a cylinder having a bottom assembly coupled to thepile to be driven, providing a descending motion of a massive pistonweight travelling within the cylinder toward the bottom assembly, whenthe descending piston weight reaches a first predetermined distance fromthe bottom assembly trapping compressible fluid within the cylinderbetween the descending piston weight and the bottom assembly to begindecelerating the descending piston weight, when the descending pistonweight reaches a second predetermined distance from the bottom assemblyinjecting pressurized compressible fluid into the cylinder between thedescending piston weight and the cylinder bottom assembly to furtherdecelerate the descending piston weight, when the descending pistonweight reaches a third predetermined distance from the bottom assemblytrapping the injected pressurized fluid within the cylinder between thedescending piston weight and the bottom assembly to completelydecelerate the descending piston weight and to re-accelerate it upwardlywith a sudden bouncing action for providing a powerful thrust to saidbottom assembly to be transmitted to the pile during the decelerationand re-acceleration of the piston weight, releasing the expandedpressure fluid from the cylinder for again providing a descending motionof the piston weight within the cylinder, and repeating the steps toprovide a sequence of powerful thrusts to said bottom assembly to betransmitted to the pile for effectively driving the pile into the earth.13. The method of extracting a pile from the earth comprising the stepsof providing a cylinder having a bottom assembly and providing an upperhead, producing a descending motion of a massive piston weighttravelling down within said cylinder directly toward said bottomassembly, as said massive piston weight is travelling downwardly andbefore the piston weight reaches the bottom assembly injectingcompressible pressurized fluid as defined herein into the region betweenthe descending piston weight and the bottom assembly to prevent saidmassive piston weight from hitting said bottom assembly and to bouncethe piston weight upwardly within the cylinder upon a cushion of saidpressurized fluid, causing the upwardly travelling piston weight toexert an upward thrust against said upper head for producing an upwardjarring action to be transmitted to the pile for extraction thereof,releasing the expanded fluid from beneath the piston weight into theatmosphere for producing another descending motion thereof, andrepeating the steps for producing a sequence of upward jarring actionsfor extracting the pile.
 14. The method of extracting a pile from theearth, as claimed in claim 13, including the step of trappingatmospheric air between the upwardly travelling piston weight and theupper head.
 15. The method of extracting a pile from the earth, asclaimed in claim 13, including the step of causing the upwardlytravelling weight to impact against the upper head.
 16. The method ofdriving a pile into the earth comprising the steps of cyclicallybounding a mass up and down upon a cushion of compressible pressurizedfluid, cyclically injecting additional compressible pressurized fluidinto the cushion beneath the mass during the cycle of operation when themass is moving downwardly, cyclically releasing expanded compressiblepressurized fluid from beneath the mass into the atmosphere during thecycle of operation when the mass is moving upwardly, and utilizing thedownward thrusts of the bouncing mass on the cushion of compressiblefluid for driving a pile.